There are over thirty five high schools that sponsor boys and girls lacrosse teams. They are governed by several leagues, by NYS Section V and by the New York State Public High School Athletic Association (NYSPHSAA).
SportsFive.NET provides a great deal of information about the boys high school programs.
The Section V Girls site provides information about the girls high school programs.
During the off-season there are a number of club teams, indoor leagues and tournaments that provide experience for high school players.